Apparatus for operating wells



Oct. 26, 1937. R. H. CARR ET AL APPARATUS FOR OPERATING WELLS Filed July 12, 1933 Lxlga/d level C071 in firm/e 1 M fave Z Z Patented ct. 26, 391i? APPARATUS FOR ornmi'rmc.

Richard H. Carr and Kenneth A. @ovell, Chicago,

IlL, assignors to The Pure Oil Company, Ghicago, EL, a corporation of Ohio and apparatus for operating wells wherein a heated gaseous working fluid, such as steam, is introduced under regulated conditions into a working cylinder containing a piston from which is suspended well pumping mechanism used in elevating fluid from a subterranean well.

One of the objects of the present invention is to utilize steam, or other equivalent gaseous fluid,

in a closed or continuous cycle consisting principally of a generator or boiler, a prime mover and a condenser, and a distinctive feature of the invention c nsists in the use of a counter-balancing cylinder, ving a piston rigidly connected with that of a coacting motor cylinder, and operating in a single acting manner without valves, to the end of providing a supplementary means for counter-balancing the weight of the pumping mechanism suspended from the motor piston on a. the down stroke of the apparatus and supplying an additional force to the motor piston on the up stroke thereof. It is one of the principal aims of the invention to utilize this apparatus to increase the economy of such a pumping system by effect- '2& ing a saving in energy of the working fluid charged in the counter-balancing cylinder, since this fluid is retained in the system without any substantial reduction in pressure and to minimize waste and loss in the potential energy of the working fluid.

For a further understanding of the invention, reference is to be had to the following description and the accompanying drawing, wherein:

Fig. 1 is a diagrammatic view, partly in vertical 85 section, disclosing apparatus suitable for carrying out the ends of the present invention.

Fig. 2 is a vertical sectional view through the.

lower end of the motor cylinder showing the control valves in detafl.

Fig. 3 is a diagrammatic view, partly in vertical section showing a slight modification of the counterbalancing cylinder.

Referring more particularly to the drawing, the numeral l designates the improved pumping mechanism in its entirety. The same, in the form depicted in the drawing, comprises an assembled cylinder structure consisting of a motor cylinder 2 and a counterbalancing cylinder 3,

the said cylinders being rigidly connected in iongitudinally or vertically aligned orderwith the counter-balancing cylindert in this form of the invention disposed above and in axial registration withthe motor cylinder 2.- This-is a preferred arrangement, although it will be understood that it is within the scope of the invention to place the 1933, Serial No. 680,092

counter-balancing cylinder 1.3- other locations with respect to the motor cylinder.

The upper end of the counter-balancingcylinder is provided with a head 4 by which the entire cylinder structure may be suspended from a derrick -or other support (not shown) in order that the cylinder structure may be disposed above the casing 5 of a well bore. In the bottom of said casing or well bore, there is usually arranged a submerged pump which is to be operated by the motor mechanism 1 so as to expel liquid from the bore and lift it to an elevated point of discharge as indicated by the valved pipe line 6. In order to operate this submerged pump, use is made of a string of sucker rods 6, or the equivalent thereof such as a cable, which extend through the bore and have their upper end connected with the usual polish rod 1. In this instance, the polish rod is connected with a piston rod 8 connected, in turn, at'its upper end with a motor piston 9 slidably mounted in the cylinder 2, the rod 8 extending through a packing gland l0 provided in the closed lower end H of the motor cylinder. By this construction, when the piston 9 is reciprocated, the submerged pump in the well bore is operated to force liquid upwardly and out of the bore. In the cylinder 3, there is provided a piston H which is rigidly connected by a rod I3 which extends through the closed upper end of the cylinder 2 and is united with the piston 9, whereby both of said pistons move in unitary relationship in their respective cylinders. The counter-balancing cylinder 3 and its piston I! are preferably of considerably smaller diameter than the motor cylinder 2 and its piston-9, the cross sectional area of the cylinder 2 andthe piston i2 being governed in accordance with the weight of the well pumping mechanism suspended from the motor piston.

The bottom of the motor cylinder ll communicates with a supply pipe i4 employed for leading a heated working fluid in a substantially gaseous state to the motor cylinder. The cylinder head ii in registratiom with the pipe 54 is provided with a passage containing an admission valve l5, and the opposite side of the head II is provided with an exhaust passage i6 containing an exhaust valve I1. Connected with the polish rod l is a frame 58 provided with adjustable lugs l9 which lugs are so disposed, as to engage with the operating cranks 20 upon the reciprocation of the polish rod. While these valves have been conventionally disclosed, they are preferably of the snap type so that upon the beginning of the upstroke or mission valve 55 is opened to provide for the inflow oi the working fluid into the motor cylinder with the exhaust valve in a closed position. The admission valve i5 is left open during a desired period of up stroke of themotor piston when it may be closed to allow for the expansion of the I working fluid during the remainder oi. the up stroke if such expansion is desired, or the admission valve may be maintained open throughout the entire up stroke of the motor piston. Upon the completion of the up stroke, however, the admission valve is closed and the exhaust valve opened to provide for the expulsion of the working fluid from the working cylinder and the controlled descent of the motor piston and apparatus carried thereby. The valve mechanism has been merely conventionally disclosed and it will be understood that other special types of valve means, specifically designed for this purpose, may be utilized.

In order to supply the cylinders 2 and 3 with a heated gaseous working fluid, such as steam, use

. is made of a generator or boiler 2| which in the form illustrated is of the vertical type. The drum 22 of the generator or boiler contains the condensable working fluid and below the drum there is arranged a heating chamber provided with a fuel burner or the like 23. The outlet stack for waste combustion products is indicated by the reference numeral 24. Leading from the top of the drum 22 is a pipe line 25 which extends to the supply pipe M of the motor cylinder and to the supply pipe 26 of the counter-balancing cylinder. The supply pipe 26 is devoid of automatic valves such as the valves l5 and I! of the working cylinder, although a hand controlled valve 21 may be located in the pipe line 26 if desired. It will be seen that this heated working fluid enters the bottom oi. the motor cylinder to efiect the elevation of the piston 8. Simultaneously, it likewise enters the lower portion of the counter-balancing cylinder to effect the elevation of the piston 12 for the purpose of assisting the action of the motor piston in raising the suspended gravity load. However, upon the down stroke ofsaid pistons, the steam or other gaseous working fluid expelled from the bottom of the counterbalancing cylinder through the line 26 is retained without reduction in pressure in the high pressure side of the system and isnot dissipated or wasted to the atmosphere. The importance of this is manifest when it is considered that many oil wells possess a depth of several thousand feet and therefore a sucker rod string or equivalent of similar length with the great weight thereof, must be suspended from the motor piston. The steam or working fluid acting against the under sides 0! said pistons during the down stroke thereof provides this measure or control by which sudden dropping 01 the suspended well operating parts is prevented and a smooth, uniform and even pumping motion is imparted to the pumping mechanism. In the event of breakage or sudden parting of the sucker rods during the up stroke of the pistons, injury to the pumping mechanism is prevented by providing the upper ends of said cylinders with valve controlled by-passes 28 by which the working fluid may be introduced into the upper ends of said cylinders from below the pistons therein to provide a cushion to arrest violent uncontrolled upward movement of the pistons.

Leading from the exhaust valve I! of the working cylinder is a pipe line 29 provided with an automatic pressure regulating valve 30 which is used to adjust the pressure under piston 9 of cylinder 2 during the down stroke. The pipe line 29 extends to a suitable condenser, air or water cooled, and for purposes of illustration, there has been disclosed a condenser coil 3| disposed in a condenser box 32 in which is contained a cooling liquid. A constant liquid level is maintained in the box 32 by the provision of a supply line 34 in which is provided a float actuated valve 35. The opening of the valve 35 in response to fluid fluctuation in the box 32, admits of the introduction of the cooling liquid obtained under pressure from an outside source into said box, in order that a substantially constant liquid level may be maintained therein. In passing through the coil 3i, the working fluid is reduced in temperature to substantially its condensing point and is discharged from said coil into a column 36 in the bottom of which the condensed fluid accumulates.

1 A valved outlet 31 is provided as a means of releasing accumulation of trapped air from the condenser. i The condensate which accumulates in the bottom of the column 36 is delivered to a hot liquid pump 38 and forced by said pump through a return pipe line 39 to the drum 22 of the generator or boiler. Several regulated systems of automatically recharging the boiler condensate and make-up fluid could be employed, but for purposes of illustration, 9. single system will be described. The pipe line 25 from which the heated working fluid is taken from the top of the generator or boiler includes a branch 40 which extends to the steam chest of the pump 38. In the line 40, there is provided a quick opening type valve 4| which is responsive to the liquid level in the bottom of the column 36. A substantially. uniform liquid level is maintained in the bottom of'the column 36, and should this liquid level recede below a desired point, the valve 4| is automatically operated to discontinue steam supply to the pump 38, thereby arresting its operation and shutting off condensate flow through the line 39.

To supply deficiencies in the quantity of the working fluid, due to leakage, evaporation and other losses-there is also employed a. make-up pump 42. nected with a source of water or other fluid supply by means of the line 43 and the outlet side of the pump is connected by a branch 44 with the pipe line 39. Steam for operating the pump 42 is obtained from a branch 45 of the pipe line 40 and in the branch 45 there is disposed an automatic control valve 46 having its diaphragm chamber connected by means of a line 41 with the pipe line 39 on the farside of the check valve 48.

The suction side of this pump is con- Therefore, should the liquid pressure in the pipe line 39 be diminished below a desired point, due to lack of fluid supply, the valve 46 opens to admit steam to the steam cylinder of the pump 42, causing its automatic operation and the pumping of water, or other working fluid, from an extraneous source into the system to compensate for deficiencies in the supply of such working fluid in the closed cycle of the system.

The drum 22 of the steam boiler or generator is provided with a liquid level controlsystem 49, 50 and II, which serves to open a valve on pipe line 39 when liquid in the generator or boiler is reduced below a desired point and which closes a valve or restricts flow in pipe line 39, when the liquid level in said boiler reaches or exceeds a desired point. The regulator 68 is connected with a valve 5| provided in the line 39 adjacent to the point where the latter enters the drum 22. The numeral 62 designates a gage glass on the boiler,

quantity of fuel when the pressure in line 25 reaches a predetermined low point, or by a decreased quantity of fuel to burner when pressure in line 25 reaches a predetermined higlr point.

In addition, the boiler or generator may be provided, with standard poppet valves, fusible plugs, test cocks and other usual boiler safety equipment.

In view of the foregoing, it will be seen that the present invention provides for increasing the economy of a fluid pumping system of the character set forth by a saving in energy of the steam, pr other heatedworking fluid, charged to the counter-balancing cylinder, as such steam is retained in the cyclic system without substantial reduction in pressure. For instance, when steam is used as the motivating fluid, a saving can be made of the order of 25% to 30% in the matter of steam consumption over the steam requirement necessary for performing similar work but without using the counter-balancing .InFig. 3 a

mechanism. The operation of the system is substantially automatic, safety features have been provided for protecting its function and the operators and attendants and for maintaining sustained operation for indefinite periods of time without requiring interruptions in; the conti-e unity of operation to effect adjustment and repairs.

slight modification of our invention has been set forth wherein the counterbalancing cylinder 30. is provided with its own motivating fluid circuit, which may be independent of that employed for the operation of the motor cylinder, thereby providing for a more accurate regulation of the operation of the piston of the cylinder 3a. A pipe line Bil enters the bottom; of} the cylinder 3a and said line is equipped with a receiver 6! and a regulator valve 62 by which uniform pressures in the cylinder 3a.

may be maintained, the line leading'to a source of supply for the motivating fluid which may be air, steam or gaseous fluid under pressure. J

It will be understood that the apparatus illustrated and. hereinbefore specifically described is merely exemplary of the operative features of the present invention and that the principles of the invention may find expression in other wide- *ly differing types of. apparatus without departing from the scopeof the invention as the latter has been defined in the following claims.

What is claimed is:

1. Apparatus of the character described comprising a single acting motor cylinder, a piston slidably mounted therein, a rod connected to said piston and a gravity load connected to said rod, a counter-balancing piston slidably mounted in a second cylinder and connected with the piston in said motor cylinder in such manner as to operate in harmony therewith, means for supplying fluid under superatmospheric pressure to said motor cylinder, means for supplying fluid under s peratmospheric pressure to said counter-balancing cylinder, means for exhausting fluid from said'motor cylinder and means for maintaining back pressure in the motor cylinder during the exhaust stroke for the purpose of assisting in supporting the gravity load.

2. Apparatus in accordance with claim 1 including means, connected with said means for supplying fluid to said counter-balancing cylinder, for maintaining substantially constant steam pressure in said cylinder. 

